The invention relates to shelves in general, and more particularly to improvements in shelves of the type wherein a frame surrounds a grate serving to support commodities, e.g., merchandise in a store or in a similar establishment. Still more particularly, the invention relates to improvements in grates of the type wherein an endless (e.g., polygonal) frame surrounds a grate and preferably carries plugs and sockets for convenience of stacking with similar or identical shelves.